Where can I get my BE2010 license file from?

Hope someone can help or give me some guidance.

A server with BE 2010 installed stopped working correctly (BE not the server in this case) and I need to reinstall BE2010 though I don't have my BE2010 license file (.SLF). I've looked on the server and unfortunately someone installed a trial version of BE 2014  to fix the problem and for the moment I need to go back to BE2010 once I have the licence file.

So where can I get my licence file from? I have a PDF with the serial number and no one at this company knows where a copy of the licence key is stored.

Thanks,

Steve